1. Field of the Art
This invention relates generally to Diesel engine controllers, and more particularly to an engine controller suitable for application to Diesel engines construction machines such as hydraulic excavators, bulldozers, wheel loaders, tractors, motor scrapers, mobile cranes and the like.
2. Description of the Prior Art
The rotational speed of a Diesel engine, which is mounted on a hydraulic excavator or on a similar construction machine, is controlled by a governor. The governor controls the engine constantly at a speed desired by an operator irrespective of the engine load condition, or automatically controls its maximum or minimum speed. In transmitting operator's commands to the governor, it is the general practice to resort to a wire type transmission system which employs a wire to link an accelerator lever provided in the operator's station (cab) to the engine governor thereby transmitting a rotational or sliding movement of the accelerator lever to operate the governor.
On the other hand, from a standpoint of realizing remote control from a place other than the operator's station, recently there is a trend toward using an electric or fluid type transmission system which connects the accelerator lever with the governor by an electric system or by a hydraulic or pneumatic system.
However, the engine controllers with an electric or fluid type transmission system have inherent problems which often compel to stop the operation, e.g., troubles caused by disconnection and current leaks in case of the electric system and troubles caused by breakage of conduit in case of the fluid system.